This invention relates to stable fluid suspensions of poly(ethylene oxide) in aqueous carrier systems.
Prior to the present invention, poly(ethylene oxide) (PEO) has traditionally been handled in its dry, particulate form. Problems associated with dry PEO include undesirable dust generation, poor dispersibility when added to aqueous systems, and undesirably long dissolution times. The dust associated with dry, particulate PEO presents the same conventional handling problems as are encountered with other finely divided particulate materials.
Poly(ethylene oxide) (PEO) has been used as a retention aid in manufacture of paper either alone, or along with certain phenolic resins, as described in U.S. Pat. Nos. 4,070,236 and 4,313,790. An impediment to using PEO in these applications has been creating a stable solution of the PEO in water, either due to difficulties in dissolving the dry PEO or because of certain contaminants such as free chlorine or ferric ion in the water, as described in Canadian patent 1,137,261. U.S. Pat. Nos. 3,843,589 and 3,736,288 describe some of the disadvantages of solutions made from the dry polymer and suspensions using organic liquids that are non-solvents for the PEO.